Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish read-only, idempotent, non-destructive, closed-world behavior. The description adds meaningful context beyond that: the two source domains, a maximum of 10 results, the returned fields, and that full text is retrieved via `fetch`.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.